Interrupt Control Commands Summary - NEC Advanced Personal Computer System Reference Manual

Processor PCB
Table 2-5 Interrupt Control Commands Summary
READ/ I/O DATA BUS
DEVICE INSTRUCTION
WRITE ADDRESS 7 6 5 4 3 2 I
0
Master ICW I
W 20 0 0 0
I 0 0 0 I
ICW2
W 22 T7 T6 T5 T4 T3 0
0
0
ICW 3
W 22 I 0 0 0 0 0 0 0
ICW4
W 22 0 0 0 0 0 0 0 I
OCW I
W 22
M6 M5 M4 M3 M2 MI MO
OCW2
W 20
R S E 0 0 L2
Ll
LO
L 0
I
OCW3 W 20
0 E S 0
I P P R
S M
R
I
M M S
Poll Mode
R 20 I
- -
- -
W2 WI WO
Read IRR R 20
I I I I I I I
R R R R R R
R
6 5 4 3 2 I 0
Read ISR
R 20
I
I I
I
I I I
S S S S S S S
6 5 4 3 2 I
0
Read Mask R
22 M6 M5 M4 M3 M2 MI MO
Slave
ICW I W 28 0 0 0 I
0
0 0 I
ICW2 W
2A
T7 T6
T5 T4 T3 0 0
0
ICW 3
W 2A 0 0
0 0 0 I I I
ICW4 W
2A
0 0 0 0 0 0 0
I
2-22